The field of the present invention is that of exterior rear view mirrors for automotive vehicles. More particularly, the field of the present invention relates to exterior rear view mirrors for automotive vehicles having a hole or orifice to allow for removal of entrapped water and additionally having a turbulent flow generator to prevent the generation of air noise through the water removal hole.
Automotive vehicles are equipped with exterior rear view mirrors to allow the driver to see objects rearward of the vehicle. At one time, most rear view mirrors were positioned on a post that was attached to the exterior of a vehicle door or to the A pillar. In the most recent quarter-century, there has been a major effort to increase fuel economy of automotive vehicles. To achieve increased fuel economy, one technical trend has been to diminish a vehicle""s aerodynamic drag. At higher speeds, aerodynamic drag can represent nearly 50% of the power required to translate a vehicle. Therefore, any reduction in the aerodynamic drag has the potential to lead to the enhancement of the vehicle""s fuel economy.
In light of the above-noted trend, many vehicles now attach the rear view mirror assembly to a forward, upper end of the vehicle door. The rear view mirror assembly has a bracket with a mirror housing extending therefrom. The mirror housing provides an aerodynamic cover for the mirror and mounts the same. The mirror is typically pivotally mounted within the mirror housing to allow for adjustment by a powered mechanism or by manual manipulation. To allow the mirror to pivot with respect to the mirror housing, a required slight clearance between the mirror housing and the mirror is provided. The clearance between the mirror housing and the mirror allows precipitation to enter the mirror housing. Also, while a vehicle is being washed, water can enter the clearance. Although many mirror housings are fabricated from a molded plastic which will not rust, it is preferable to provide an orifice, hereinafter referred to as a water removal hole, to allow entrapped water within the mirror housing to immediately escape.
For reasons mentioned above, it is desirable that the mirror housing reduce as much any aerodynamic drag as possible that is caused by the rear view mirror. Accordingly, the mirror housing is formed to generate laminar air flow about its surfaces. In certain situations, the laminar air flow about the surface of the mirror housing can inadvertently enter into the water removal hole and generate a wind noise such as a whistle. The wind noise is resultant of a standing wave, functionally similar to the sound made when one blows across the narrow neck of an opened glass bottle of soda. The noise is more audible to a vehicle occupant since the mirror housing and bracket are exposed to the space between the body panels of the vehicle. While the wind noise has no functional degradation to the operation of the rear view mirror assembly, some vehicle drivers or occupants may find it to be mildly unpleasant.
It is therefore also desirable to provide a rear view mirror having a mirror housing with a water removal hole which does not generate wind noise.
To make manifest the above desires, the revelation of the present invention is brought forth. In a preferred embodiment the present invention provides an exterior rear view mirror assembly for an automotive vehicle. The rear view mirror assembly includes a bracket for attachment to a side portion of the vehicle. A mirror housing is connected to the bracket. The mirror housing has a rear opening and extends laterally from the bracket. A mirror is connected within the mirror housing at a position generally adjacent to the mirror housing rear opening. A water removal hole penetrates a bottom end of the mirror housing adjacent a forward end of the mirror housing to allow water entrapped within the mirror housing to escape. The mirror housing bottom end has a generally rising slope forward and adjacent the water removal hole on which three turbulent flow generators are formed. The turbulent flow generators cause turbulent airflow past the water removal hole to diminish noise being generated by the water removal hole. The turbulent flow generators have a generally triangular cross-sectional shape with a longest leg of the triangle being generally adjacent to the lower end of the mirror housing. The turbulent flow generators extend longitudinally along the travel direction of the vehicle. The two outer turbulent flow generators bracket the water removal hole.
It is a feature of the present invention to provide a rear view mirror assembly for an automotive vehicle comprising a mirror housing with a water removal hole and turbulent flow generators to diminish or eliminate the wind noise generated by air flowing through the water removal hole.
Other feature s of the invention will be more apparent to those skilled in the art upon a reading of the following detailed description and upon reference to the drawings.